Brahma On-Board Air

[subzali]

Just wanted to add a couple links, one of which came from rusty_tlc on MUD:
http://www.grungle.com/endlessair.html
http://www.jeepaholics.com/tech/OBA/oba.htm
http://www.kilbyenterprises.com/kits.htm

The SD508 supposedly is a 5 piston compressor which can put out 9cfm and 300 psi. I think the SD510 (which I have) might do slightly more cfm.

 

[LARGEONE]

I bought a VERY inexpensive military HUMV hand throttle and it works awesome. I had to modify it slightly to fit my 80, but the way that it adjusts is very nice compared to the toyota one that was available. I think I might have paid like $12. I really like the way you can turn the handle counter-clockwise and dial in the RPMs to whatever you want.

 

[60wag]

A hand throttle is good but so are power seats.


A trick I learned from Nakman: You grab your trusty snowbrush/ice scaper and rest one end on the accelerator peddle and hold the other end in front the driver seat, then move the seat forward with the power switch. Stop the seat when you have achieved optimum engine rpm for filling tires with the onboard air.

 

[subzali]

Um, FJ40 guys, no power seats

 

[AHorseThief]

Hand throttle or power seats and an ice scraper...which sounds like the sweeter upgrade?

 

[subzali]

Baby Steps...

Okay, I warned you guys this would be slow...

Got the compressor wired in today. Yep, that's it.
















When I got back inside, I was like, "alright, now all I gotta do is wire in the pressure swi---"

So not quite done with wiring it in yet, I have to see what pressure switches I have lying around and figure out how I want to wire one in.

On the other hand, I ran the compressor briefly, so at least I know it works It blew a 2A fuse, so I put a 5A fuse in there and so far so good. That wobble plate sounds a little funny, just different from other compressors I'm used to. I put my finger over the outlet port, not really sure what to expect, but it seemed like the flow was lower than I thought it would be - maybe that's because I was at 800 rpm or so. I can see why a surge tank would be a good idea. We'll see how it goes, especially if I run it at a higher rpm. :shrug:

I still have to source an inlet filter and oiler (have to figure out the thread size I guess first) and pretty much all of the pressure side plumbing components, and figure out how to mount all of it up. But getting it to run was a big step

 

[subzali]

Does anybody have any input on what on OBA compressor should feel like at idle? It feels like if I were to put my hand up to my face and blow on it, it doesn't feel like 90 psi shop air coming out of an air nozzle...

 

[subzali]

Well, got a little progress tonight. A couple days ago I noticed that my electrical connectors were pretty disorganized, so I thought that I should try to fix that a bit. I know you can buy variety packs of this stuff, but I've acquired these a little bit at a time, so this will work pretty well.

 

[corsair23]

Does anybody have any input on what on OBA compressor should feel like at idle? It feels like if I were to put my hand up to my face and blow on it, it doesn't feel like 90 psi shop air coming out of an air nozzle...

Not a clue Matt but if you don't get an answer, you could always swing by sometime and we can fire up my 40 and the York and compare

 

[Uncle Ben]

Does anybody have any input on what on OBA compressor should feel like at idle? It feels like if I were to put my hand up to my face and blow on it, it doesn't feel like 90 psi shop air coming out of an air nozzle...

A compressor by itself (even your home compressor) only puts out 10 CFM (few CFM more or less) Add in the storage tank and now you "compress" the air and create pressure. Just like the air from your mouth....open your mouth and breath out air onto your hand.....meh. Now blow that same air through your puckered lips and you can feel it... same air....less volume more pressure. Try sealing off the output hole from the compressor with your finger....bet ya cant.

 

[subzali]

Well, got a little progress tonight. A couple days ago I noticed that my electrical connectors were pretty disorganized, so I thought that I should try to fix that a bit. I know you can buy variety packs of this stuff, but I've acquired these a little bit at a time, so this will work pretty well.

I have no idea why I have all those yellow wire nuts...

 

[DaveInDenver]

Does anybody have any input on what on OBA compressor should feel like at idle?

Asks the E.I. studying for his test...

 

[subzali]

Asks the E.I. studying for his test...

Okay, so quick napkin calc:

SD-510 has approx. 10 cu. in. displacement.

I had my engine idling at about 800 rpm. Assuming the compressor pulley is approximately the same diameter as the crank pulley:

At 800 rpm, compressor output = 4.6 cfm with no backpressure

If the discharge connection is 3/4", then that is approx. 21 ft/s discharge velocity. Yeah, I guess that's about what I felt.

:shrug:

At 2000 rpm, compressor output should be about 11.6 cfm with no backpressure, so looks like I need to figure out a hand throttle

 

[DaveInDenver]

Answered your own question and got a little more prepped! Any word yet from the AES board?

 

[subzali]

No, which I'm getting worried about. You got your letter on 1/8/2008. The deadline to register with NCEES is February 23. I should probably call the state and find out what's going on. There were some problems with my application because they changed the format of the application halfway through the time I was filling it out.

 

[Red_Chili]

For a cheap but righteous hand throttle... bicycle shifter mounted on your gear shift. Modify the gas pedal to accept another cable, or, cable it to somewhere on the carb itself.

You can use it for those pucker moments starting on a steep hill too...

Arapahoe Cyclery should be able to fix you up with all you need.

 

[subzali]

For a cheap but righteous hand throttle... bicycle shifter mounted on your gear shift. Modify the gas pedal to accept another cable, or, cable it to somewhere on the carb itself.

You can use it for those pucker moments starting on a steep hill too...

Arapahoe Cyclery should be able to fix you up with all you need.

you know Bill, earlier 40s came with a hand throttle, so I think I'm going to keep it "Toyota" on this one

 

[Uncle Ben]

you know Bill, earlier 40s came with a hand throttle, so I think I'm going to keep it "Toyota" on this one

Nicely played!

 

[Red_Chili]

Dash mount? How much?

 

[DaveInDenver]

dash Mount? How Much?

Under the dash and pulls on the pedal, it's no-nonsense. I love the straight forward solutions on FJ40s, it's what ghetto engineers would do if they had a factory at their disposal.